Calibration method of strap-down inertial measurement unit based on single-axis rate turntable

The traditional calibration method of a strap-down inertial measurement unit (SIMU) is by "position and rate". It takes a long time, needs aiming-north and high-grade calibration equipment. This article proposes a calibration method of the SIMU based on a single-axis rate turntable, which requires only one single-axis rate turntable. When the x, y and z axes of the SIMU are set vertical-up and vertical-down respectively, the rate turntable is rotated one round at a constant speed. The error coefficients of the SIMU are calculated by mathematical transformation on the attitude angles of the rate turntable and the measurement models of the SIMU. This article establishes the calibration models, deduces the separation algorithm of error coefficients, arranges the calibration flow and presents the data processing method. The effectiveness of this method is validated by a test. For the calibration method based on a single-axis rate turntable, its requirement for calibration equipment is low. In addition, it needs no aiming-north and the calibration time is short. Therefore, this method is suitable for the calibration of a SIMU of medium precision.